250x cam

i know this has all been discussed many times. but what i am looking at is this. i recently put a 80mm big bore kit in my 250x. it still has the stock cam. i had a nice newer model 300ex carb which is a 32mm, so i put it on and rejetted. problem is, i don't think that it is getting enough gas. i have a 400ex carb on its way from gdh racing so this should help. i know i need a bigger cam with more duration but i really don't want to change valve springs and rockers. i don't have so much of a problem with getting the hard weld rockers as i do running those stiff a** springs. i have seen what they do to the valve tips, not to mention the extra stress on the timing chain parts. i guess what i am asking is; will the hotcams stage one be enough to make my big bore kit run good? if not, what cam do i need to buy and can i even get a cam that would make this engine run well without having to change the valve springs. i don't need to squeeze every ounce of power out of it, but i do know that my current cam and carb set up is not enough. my big bore kit is rated at 11.5 to 1 compression. i put new valves, guides, etc. in the head. i have a 400ex carb coming and i am running a fmf megamax 2 exhaust. my sprockets are still stock 13/38 with 20 inch rear tires. any help or tips much appreciated.